IT professionals keep technology running smoothly at companies around the world so everyone else can do their job. But often, these hard-working, computer-savvy professionals are tasked with fixing everything and anything electronic, with little or no budget for software.

Thankfully, some helpful IT tools are available for free. But not all no-cost IT software is created equal. With freeware tools, sometimes you get what you pay for and busy IT workers don't have time to individually test every application to separate the good apps from the not so good.

Great free tools for IT professionals

Often, the best way to find out about free IT tools and utilities is from others who have hands-on experience. And over the years, IT pros in Spiceworks have recommended many high-quality, free software tools to each other. We combed through many "best of" posts and reviews in Spiceworks to create this list of IT tools that are either completely free for commercial use or provide a free version that can serve a legitimate business purpose with an option to upgrade if more functionality is needed.

USB Stick

What's on your stick? With cloud technology pervasive in the networking arena these days the use of a USB stick and the sneaker-net is less common., However, I still keep a USB stick around my neck at work just in case! Here are the tools I keep:

Malwarebytes Free - One of the best and longest lasting tools. The free version still works good.

CCleaner - CCleaner is the number-one tool for cleaning your PC. It protects your privacy and makes your computer faster and more secure!

HouseCall from TrendMicro - Free- HouseCall can quickly identify and fix a wide range of threats including viruses, worms, Trojans, and spyware.

RootkitBuster - Free - I generally run this first on a suspected system and then run HouseCall.

Free Backup Software

If you're looking for low-cost or no-cost enterprise backup solutions for PCs and servers, check out these 5 free backup tools for IT pros. Most are completely free, while others are free versions of more powerful paid products, with a few small limitations.

Veeam Endpoint Backup Free — free for unlimited Windows-based desktops and laptops, this software can help anyone back up PCs to external hard drives or networked storage. (reviews)

Notepad++ — a highly-rated free text editor for Windows that supports syntax highlighting for many file formats that's available under the GNU General Public License (GPL), meaning it's free to use by anyone, including businesses. (reviews)

Free Boot CD and Utilities

If your operating system won't boot due to hard disk problems or a corrupted master boot record (MBR), boot discs or bootable USB sticks can help you recover files or figure out what's wrong.

Ultimate Boot CD — a "completely free" boot disc that includes many diagnostic, disk, boot management, and benchmarking tools. Many IT pros consider it an essential tool in the IT pro arsenal. (reviews)

Knoppix — a fully functional Linux distribution / live CD that's bootable from a USB drive, making it useful if you need to rescue data (reviews)

Hiren's Boot CD — another bootable CD that includes many tools for data recovery, disk imaging, and general computer troubleshooting (reviews)

Free Disk Utilities

Whether you need to image a disk, permanently delete files, or blow away an entire hard drive, these free tools have you covered.

DBAN (Darik's Boot And Nuke) — DBAN is one of the best wipe tools for hard drive disposal. If you need certification of erasure for compliance reporting, however, you should upgrade to the paid version

File Shredder — a free utility that can help you permanently delete Windows files and folders without leaving any trace, so they can't be recovered later. (review)

Disk Wipe — a free Windows application for permanent data destruction that is "free for personal or commercual use, without any restrictions." (review)

CloneZilla — a bootable disk imaging and cloning utility similar to other paid tools. Best of all, Clonezilla is free and open source. (review)

IMGBurn — a lightweight application that can help you burn CDs, DVDs, HD DVDs, or Blu-rays for free. (review)

FOG Computer Cloner — a Linux-based, free and open-source computer imaging solution for Windows that works via TFTP and PXE. No boot disks required, you can deploy images to multiple systems over the network. (review)

Free File Utilities

7zip — file compression software that's free and open source and can be used on any computer in a commercial organization (reviews)

FreeFileSync — a GUI-based, rule-based file syncing tool that can help you perform complex sync operations. The tool is open-source and works on Windows, Linux, and Mac OS X folders. (reviews)

WinDirStat — free software that provides disk usage statistics and cleanup tools for Microsoft Windows so you can see which files and directories are hogging disk space and do something about it (reviews)

Free File Transfer Utilities

Filezilla — a popular, open source FTP client and FTP server that's free, open source, and distributed under the GNU General Public License (reviews)

Martin Prikryl WinSCP — an open source SFTP client and FTP client for Windows known for it's distinct lack of bloatware that can facilitate secure file transfers between computers (reviews)

Free Virtualization Software

Oracle VM VirtualBox — a very useful open-source (GNU license for the base package) hypervisor that runs on top of your existing OS. VirtualBox runs on Windows, OS X, Linux, and Solaris hosts and supports a huge range of guest OSes including major Windows releases, Linux, OS/2, OpenBSD, DOS, OSX, and more. While free, additional features in the optional extension pack need to be licensed for commercial use. (reviews)

Disk2VHD — a freeware tool that helps you do physical to virtual conversions (P2V) by generating a Virtual Hard Disk (VHD) file for use with . (reviews)

vCenter Converter — freeware that allows you to create VMware virtual machines by converting from Windows or Linux physical machines, or other VM formats. (reviews)

Microsoft Management Tools

Windows SysInternals — a collection of advanced system utilities for designed to help IT professionals manage, troubleshoot, and diagnose their Windows systems. (Reviews for Autoruns, Process Monitor, BgInfo, Active Directory Explorer)

Connectivity Dashboard — monitor and view speed to their applications. Figure out if there’s an issue with the ISP, application, or something else onsite with this network troubleshooting tool. (review)

PDQ Deploy — this time-saving tool helps you deploy patches and common applications to multiple systems across your network. According to IT pros, the free version provides plenty of features if you don't want to upgrade to the pro version (review)

The Dude — free, cross-platform network monitor application that can scan and map your network and alert you if there are any problems (reviews)

Wireshark — an open-source, multi-platform packet analyzer tool you can use to scan network traffic. (reviews)

Cacti — an open-source, multi-tenant network monitor and graphing tool for Unix or Windows. It uses industry standards like SNMP to poll and graph info on CPU, bandwidth utilization, memory and more. (reviews)

Zabbix — an open-source, Linux-based, real-time network monitoring system for various network services, servers, and hardware. It can monitor up to 100,000 devices and provide up to 1,000,000 metrics. (reviews)

PRTG — an all-in-one monitoring solution for Windows, which continuously collects status information from IT infrastructure and informs you about malfunctions and allows you to pro-actively reduce downtime. The free version is limited to monitoring 100 sensors / switch ports. (reviews)

Free Software Firewall + IDS / IPS

Numerous free, software-based firewalls can help protect your business from external threats and some can even analyze incoming traffic for intrusions.

pfSense — a free, open-source, FreeBSD-based software firewall distribution that can also be deployed as a router, wireless access point, DHCP server, DNS server, or VPN endpoint and with integrations, can also serve as an IDS or IPS solution. (reviews)

Untangle — a software-based next generation firewall platform with an intuitive GUI interface that's popular among IT professionals. The free version includes firewall, IPS, and some web filtering functionality, although you can pay to unlock additional features (reviews)

Snort — free and open source network intrusion detection and prevention software used by many IT departments to secure their network (reviews)

IPCop — A Linux-based, open source firewall that's geared towards small office and is a favorite among some IT pros (reviews)

Smoothwall Express — A Linux-based open source firewall solution that's been around since 2000, and has an easy-to-use web interva (reviews)

Free Network Scanners

Advanced IP Scanner — Windows freeware that can locate all computers on your network quickly and allows for some remote control of devices via RDP and Radmin (reviews)

Angry IP Scanner — a cross-platform, open source network scanner that can help you quickly find devices on your network. Available for Linux, Windows, and Mac OS X (reviews)

NMAP — a cross-platform, open source network security scanner that can help you create a map of your network. Nmap can scan for exposed ports and services, which can help you identify vulnerabilities and make your network more secure. (reviews)

Free Help Desk Software

Spiceworks Cloud Help Desk — help desk software with nothing to install. Build, a multi-user help desk with no limits so you can tackle tickets and solve IT problems quickly, and get back on with your day.

Free Remote Desktop / Remote Control Software

Microsoft Remote Desktop Protocol (RDP) — included in most Server, Pro, and Enterprise versions of Windows for decades, RDP allows IT pros to remotely control computers from afar, although it doesn't include some of the screen mirroring functionality that third-party remote desktop assistance software does. (reviews)

VNC variants — freeware that allows you to mirror someone else's screen on yours remotely and control the mouse and keyboard too. Very useful for IT professionals who need to manage and debug many PCs.

Remote Desktop Manager (Devolutions) — A cross-platform remote desktop tool that works on Windows, OS X, Android, and iOS and supports multiple session types including RDP, VNC, Apple Remote Desktop, TeamViewer, and LogMeIn. A completely free version is available, with additional connectivity, password management, security, and document management features unlocked if you upgrade to the paid Enterprise edition. (reviews)

Free Office Productivity Software

LibreOffice — LibreOffice is free, open-source office suite software for Windows, Linux, OS X. It includes software for word processing, spreadsheets, presentations, vector graphics and flowcharts, databases, and formula editing and is a branch of the OpenOffice project. (reviews)

Apache OpenOffice — An open source, multi-platform office suite that includes word processing, spreadsheets, slideshow presentations, and more. It can be downloaded and used completely free of charge for any purpose. (reviews)

Free Web-based Network Tools from Spiceworks

Subnet Calculator — does the difficult math of subnetting for you, so you can more easily divide an IP network into smaller subnets, displaying subnet masks, IP ranges, and CIDR notations graphically.